Polyunsaturated fatty acids (PUFAs), including omega-3, omega-6 and omega-9 fatty acids, are vital to everyday life and function. For example, the beneficial effects of omega-3 fatty acids like all-cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and all-cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) on lowering serum triglycerides are well established. All-cis-9,12,15-octadecatrienoic acid (ALA) is the precursor essential fatty acid of EPA and DHA. All-cis-5,8,11,14-eicosatetraenoic acid (AA) and its precursors all-cis-6,9,12-octadecatrienoic acid (GLA) and all-cis-9,12-octadecadienoic acid (LA) have been shown to be beneficial to infants.
Several of these compounds are also known for other cardioprotective benefits such as preventing cardiac arrhythmias, stabilizing atherosclerotic plaques, reducing platelet aggregation, and reducing blood pressure. See e.g., Dyrberg et al., In: Omega-3 Fatty Acids: Prevention and Treatment of Vascular Disease. Kristensen et al., eds., Bi & Gi Publ., Verona-Springer-Verlag, London, pp. 217-26, 1995; O'Keefe and Harris, Am J Cardiology 2000, 85:1239-41; Radack et al., “The effects of low doses of omega-3 fatty acid supplementation on blood pressure in hypertensive subjects: a randomized controlled trial.” Arch Intern Med 151:1173-80, 1991; Harris, “Extending the cardiovascular benefits of omega-3 fatty acids.” Curr Atheroscler Rep 7:375-80, 2005; Holub, “Clinical nutrition: 4 omega-3 fatty acids in cardiovascular care,” CMAJ 166(5):608-15, 2002. Indeed, the American Heart Association has also reported that omega-3 fatty acids can reduce cardiovascular and heart disease risk. Other benefits of omega-3 fatty acids are those related to the prevention and/or treatment of inflammation and neurodegenerative diseases, and to improved cognitive development. See e.g., Sugano and Michihiro, “Balanced intake of polyunsaturated fatty acids for health benefits.” J Oleo Sci 50(5):305-11, 2001.
The fatty acids EPA and DHA can be synthesized in the human body from ALA; however, the conversion rate from this precursor molecule is limited (Muskiet et al., “Is docosahexaenoic acid (DHA) essential? Lessons from DHA status regulation, our ancient diet, epidemiology and randomized controlled trials,” J Nutr 134(1):183-6, 2004). Accordingly, EPA and DHA in the body are primarily derived from dietary sources (e.g., traditionally oily fish and, more recently, microbial sources such as fungi and algae). Diets rich in fish oils are known to have many beneficial effects for heart disease, cancer, arthritis, allergies, and other chronic diseases. Epidemiological clinical trials have shown that increasing the dietary intake of PUFAs such as omega-3 fatty acids, in the form of fish or of fish oil supplements, may reduce various risk factors associated with cardiovascular disease. See e.g., The American Heart Association, Scientific Statement, “Fish Consumption, Fish Oil, Omega-3 Fatty Acids and Cardiovascular Disease,” November 2002; Appel et al., “Does supplementation of diet with ‘fish oil’ reduce blood pressure? A meta-analysis of controlled clinical trials.” Arch Intern Med 153(12):1429-1438, 1993; GISSI-Prevenzione Investigators. “Dietary supplementation with omega-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial.” Lancet 354:447-55, 1999.
In addition to fish oil sources of EPA and DHA, these PUFAs, as well as ALA, AA and GLA, can be and are derived from microbial sources including, without limitation, Mortiarella alpina for ARA and various species of Thraustochytrids for DHA and EPA. Plants are now being modified genetically to include genes that produce various PUFAs in further efforts to reduce costs associated with commercial production of these oils.
Despite the strong evidence for the benefit of PUFAs like EPA and DHA in prevention of cardiovascular disease, the average daily consumption of these fatty acids by North Americans is estimated to be between 0.1 to 0.2 grams, compared to a suggested daily intake of 0.65 grams to confer benefit (Webb, “Alternative sources of omega-3 fatty acids.” Natural Foods Merchandiser 2005, XXVI (8):40-4). Since altering dietary patterns of populations is difficult, many people do not like to eat fish, and the notion of consuming oils derived from microbes has not achieved general acceptance, the supplementation of diets with PUFAs is an important approach to addressing this problem. Unfortunately, many PUFAs are sensitive to oxidation and can have unpleasant sensory properties.
In light of the health benefits of PUFAs such as omega-3 and omega-6 fatty acids, it is desirable to find new ways to improve their sensory and storage stabilities. The ability to improve sensory and oxidative characteristics allows PUFAs to be incorporated into a wider variety of comestible compositions, supplements, and pharmaceutical formulations. The compositions and methods disclosed herein address these and other needs.